USGS WPhase Moment Solution
COSTA RICA
12/ 9/ 8 20:29:32.00 Epicenter: 10.095 -85.321 MW 5.7 USGS/WPHASE CENTROID MOMENT TENSOR 12/ 9/ 8 20:29:32.00 Centroid: 9.995 -85.422 Depth 19 No. of sta: 29 Moment Tensor; Scale 10**17 Nm Mrr= 2.24 Mtt=-1.40 Mpp=-0.84 Mrt= 3.32 Mrp=-0.93 Mtp= 0.79 Principal axes: T Val= 4.24 Plg=59 Azm= 9 N = -0.42 6 110 P = -3.82 29 204 Best Double Couple:Mo=4.0*10**17 NP1:Strike=314 Dip=17 Slip= 114 NP2: 109 75 83
The figure above shows a visual representation of the style of faulting (focal mechanism)
derived from the estimated moment tensor.
Shaded areas show quadrants of the focal sphere in which the P-wave first-motions
are away from the source, and unshaded areas show quadrants
in which the P-wave first-motions are toward the source.
The dots represent the axis of maximum compressional strain
(in black, called the "P-axis")
and the axis of maximum extensional strain (in white, called the "T-axis")
resulting from the earthquake.
